Singapore: World No. 1 Serena Williams has rarely suffered a humiliating loss in her glittering career, so the 33-year-old American was quick to praise her coach for dragging her out of the pit of despair to return to winning ways on Thursday.

A day after she was thrashed by Simona Halep in round-robin play at the WTA Finals in Singapore, Williams was back to her brilliant best in handing out a 6-1, 6-1 drubbing of Canada’s Eugenie Bouchard to close in on a semi-finals berth.

The 18-times Grand Slam champion admitted she felt her tournament was over after Halep dismantled her game so ruthlessly in a 6-0, 6-2 romp, but thanked coach Patrick Mouratoglou for giving her advice and the motivation to give her all back out on court.

“I was really disappointed in my play yesterday [Wednesday]. I tried, but it didn’t work out for me,” Williams told reporters of her defeat.

“I don’t really recover well from losses, but I had a really long talk with Patrick. He just was telling me what I needed to do and how to get over it.

“He was like, ‘You’re still in the tournament. You still have another match to play. You can’t dwell on this’. But he said it over and over in differing ways, just talking positive. I started to believe that maybe I could come play another match.

“I wasn’t quite sure that I could. So he really was able to help me out.”

The Frenchman’s advice worked wonders for Williams as she steamrollered through Bouchard’s serve to claim victory in just 59 minutes.

Now Halep can do the American a favour if she takes a set off Ana Ivanovic in the final Red Group tie today.

Should Ivanovic fail to win in straight sets, the world number one will advance to a semi-final she felt was out of her grasp until her coach gave her the confidence to beat Bouchard.

“He told me that I didn’t have the same attitude that I normally have when I approach a match,” Williams said of the Halep encounter. Williams came into the event under a cloud after she and her sister Venus were the target of what she described as “sexist, racist and bullying” comments by Russian tennis boss Shamil Tarpischev. But she said on Thursday he had apologised.

“Yes, I have received [an apology],” she said. “He has reached out to both myself and my sister. It was written, so I did not speak to him.”